1. Field of the Invention
The present invention relates to a mechanism for moving a reel assembly, and a tape cassette sensing switch, for use in a magnetic recorder capable of using two different sized tape cassettes, such as one for a video cassette recorder (VCR), one for a camcorder, one for a digital-video cassette recorder (D-VCR) and the like. More particularly the present invention relates to a simplified mechanism for moving a reel assembly, and a tape cassette sensing switch in a magnetic recorder, capable of reducing fabricating cost and enhancing reliability and performance of the recorder.
2. Description of the Related Art
With the recent enhancement of performance and functions of magnetic recorders such as VCR, D-VCR and the like, various kinds of tape cassettes for use in the magnetic recorders have been provided according to various user preferences. The tape cassettes are formed of various different materials, perform recording jobs in different manners, are fabricated by different methods, and have a record protecting function. Also, the sizes of the tape cassettes vary.
In addition, with the improvement of technology in the magnetic recorder industry, a technology for selectively using different sized tape cassettes in a single magnetic recorder is being attempted.
As a prerequisite to selectively using different sized tape cassettes in a magnetic recorder, a reel driving mechanism must be movably structured to accommodate the different sized tape cassettes.
There have been disclosed various techniques for accommodating different sized tape cassettes in a magnetic recorder by structuring a reel driving mechanism that is movable in a predetermined direction.
As an example, Japanese Patent Laid-open No. 8-167198 (1996) discloses a reel disk braking mechanism including: (1) a pair of reel disk bases for moving a pair of reel disks installed in such a manner that the distance between the reel disk bases can be adjusted to a distance corresponding to the distance between reels of a first cassette when the first cassette is used, and a distance corresponding to the distance between reels of a second cassette when the second cassette is used; (2) brake arms supported by respective shafts installed on the reel disk bases; (3) brake pads installed on respective ends of each of the brake arms; and (4) a pair of slide cams. The pair of reel disk bases are capable of bringing the brake pads in contact with respective reel disks, or separating the brake pads from the respective reel disks at any position corresponding to the distance between the reels of the first and the second cassettes.
However, in such a conventional technique, brake assemblies are loaded on respective reel disk bases. Accordingly, a great amount of power is required for moving the reel disk bases. Moreover, necessary structure for the great amount of power transmission, as well as interference between the brake assemblies and other adjacent components, must be taken into consideration. This results in a complicated structure and an increased cost.
In addition, reliability of performance may be reduced because the relatively complicated and heavy brake assemblies are loaded on the reel disk bases when moved.
Furthermore, the magnetic recorder utilizing two different sized tape cassettes requires a tape cassette sensing device for recognizing information on the characteristics of the tape cassettes. However, such a tape cassette sensing device is not included in the conventional technique. Accordingly, a tape cassette sensing device may be separately structured and a power source for driving the tape cassette sensing device is required. This results in a more complicated structure.